The present invention relates to a method for inspecting defect and an apparatus for inspecting defect in a production line for a semiconductor device, liquid crystal, magnetic head, or other device, and more particularly to a technology for inspecting foreign matters (particle)/defects existed on a processing substrate formed circuit patterns.
An example of semiconductor wafer inspection will now be described.
In a conventional semiconductor manufacturing process, any foreign matter existing on a semiconductor substrate (wafer) may cause a wiring insulation failure, short circuit, or other failure. Furthermore, since the semiconductor elements have turned minutely, when a fine foreign matter exists in the semiconductor substrate, this foreign matter causes for instance, insulation failure of capacitor or destruction of gate oxide film or etc. These foreign matters are mixed in the semiconductor substrate by various causes in the various state. As a cause of generating of the foreign matters, what is generated from the movable part of conveyance equipment, what is generated from a human body and the thing by which reaction generation was carried out by process gas within processing equipment, the thing currently mixed in medicine or material used can be considered. A liquid-crystal display device will become what cannot be used, if a foreign matter mixes on a circuit pattern or a certain defect produces a liquid-crystal display device manufacturing process similarly. The situation of the same is said of the manufacturing process of a printed circuit board, and mixing of the foreign matter becomes the short circuit of a pattern, and the cause of poor connection.
A certain conventional technology for detecting the above-mentioned foreign matters (particles) on a semiconductor substrate, which is disclosed, for instance, by Japanese Patent Laid-open No. 62-89336, illuminates laser light to the semiconductor substrate, detects the light scattered from any foreign matter on the semiconductor substrate, and compares the obtained result against the inspection result of the last inspected semiconductor substrate of the same type to conduct a high-sensitivity, high-reliability, foreign matter/defect inspection while averting a pattern-induced false alarm.
As one of the technology which detects the foreign matter on this conventional kind of semiconductor substrate, as indicated by a prior art 1 (Japanese Patent Laid-open No. 5-218163), loses the misreport by the circuit pattern, and it enables inspection of the foreign matter with the defect high sensitivity and the high reliability, by illuminating laser beam to the semiconductor substrate, detecting the scatter light generated from the foreign matter when the foreign matter is adhered on the semiconductor substrate and comparing with the inspection result of the semiconductor substrate of the same kind inspected immediately before.
Moreover, one of technology of inspecting the above-mentioned foreign matter is known a method for illuminating coherent light to the wafer, removing the light ejected from the repetition circuit pattern on the wafer by a spatial filter, and emphatically detecting the foreign matter and the defect without repetition nature. The foreign matter inspection apparatus which illuminates light from a direction angled 45 degrees for the main straight line groups of this circuit pattern to the circuit pattern formed on the wafer and does not input 0-order diffraction light from main straight line groups into an opening (a pupil) of an objective lens, is known by a prior art 2 (Japanese Patent Laid-open No. 1-117024).
Prior arts relating with an apparatus and a method for inspecting the defect of the foreign matter or the like are known as a prior art 3 (Japanese Patent Laid-open No. 1-250847), a prior art 4 (Japanese Patent Laid-open No. 6-258239), a prior art 5 (Japanese Patent Laid-open No. 6-324003), a prior art 6 (Japanese Patent Laid-open No. 8-210989) and a prior art 7 (Japanese Patent Laid-open No. 8-271437).